Various kinds of equipment operating by being fed with a compressed gas, such as air or carbon dioxide, are known, wherein gas must be fed into an expansion chamber at a relatively high pressure and later ejected by pulses to act upon an actuator element or another operating part of the equipment.
Similar uses are known, for instance, in percussion tools or in air weapons, or “softair” weapons.
Particularly, the latter have a compressed air tanks for controlled supply of a chamber with a bullet therein, to impart a high-energy pulse thereto for bullet ejection.
Fluid delivery control devices are also known, which control instant release of the energy associated with a compressed working fluid in an actuator device.
Nevertheless, the compressed gas supply systems of these devices have a poor efficiency and are not easily rearmed, particularly when manually operated gas compression systems are used.
On the other hand, if the compressed gas is contained in a tank to be connected to the bullet loading chamber, a considerable waste of fluid occurs at each shot.
U.S. Pat. No. 3,102,553 discloses a valve device for controlling pressurized fluid delivery, comprising a hollow body with an inlet and an outlet for a pressurized fluid.
A movable valve element is housed in the hollow body, and is adapted to selectively open and close the outlet to control fluid delivery and ejection.
Particularly, two separate variable-volume chambers have been formed in the hollow body, which are supplied with respective pressurized fluids through separate supply circuits, such that opposed forces may be exerted on the valve element, which will close the outlet under equilibrium conditions.
In order to break the equilibrium and allow the valve element to slide and clear the outlet and allow gas ejection, additional pressure must be provided at one of the two sides of the valve element by supplying an additional volume of fluid through a third supply conduit.
This solution appears to be particularly complex and difficult to use in equipment, such as tools and weapons, that must ensure practical use.
Namely, control of pressure of the various fluids requires connection of the various conduits to separate external fluid supply circuits.